to Bleeping Computer.Heuristic analysis
is the ability of an anti-virus program to detect possible new variants of malware
before the vendor can get samples and update the program's definitions for detection. Heuristics uses non-specific detection methods to find new or unknown malware which allows the anti-virus to detect and stop if before doing any harm. A heuristic scanner does not compare code to a signature file like a virus scanner but uses a grading system to determine the probability that the program code being analyzed is a virus. Most heuristic scanners perform a statistical analysis in order to determine the likelihood that a file contains program code that may indicate it is malicious. Static heuristic analysis usually begins by scanning code for suspicious attributes characteristic of a malicious program. Dynamic heuristic analysis involves copying part of a programs code into the anti-virus's virtual emulation buffer and uses special techniques to reproduce its action (execution). If any suspicious activity is detected during this phase, the program is considered malicious and its execution is blocked.
to using heuristics is that it is not as reliable as signature-based detection (blacklisting) and can potentially increase the chances that a non-malicious program is flagged as malicious. With heuristics, there is always a potential risk
for a "false positive
" when the heuristic analysis flags a file as suspicious
that contains no malware. Packed files
use a specially compressed (protected) file that may have been obfuscated or encrypted in order to conceal itself and often trigger alerts by anti-virus software using heuristic detection because they are resistant to scanning (difficult to read). Sometimes lowering the program's heuristic settings
and rescanning may provide more accurate results but then that increases the possibility for new malware to infect your system.
With that said...as a new member be sure to read the Welcome to Bleeping Computer! Guide
and the following...
The BC Staff